How to bake multiple fluid simulations in one scene?
Here we share our results based on the method explained {here} and {here}.

The idea is simple:  


  1) define domain, fluid, obstacle etc
  2) assign unique folder for baking cache
  3) bake the fluid one
  4) remove domain and fluid associations


Repeat the above as many times you want (here in the following example we did it three times).
Trick:  Indeed, for the following example we just baked once. Then we copied domain+obstacle two times. Relocated them on the scene. Duplicated all the cache on the disk two times in two folders that later we assigned in the above algorithm :))

We also used offset frame just to make the fluids a little bit different in stage:)

Note: domains can overlap or whatever, but notice that the fluids do not interact each other but overlay.